Bell hoist



Feb. 15, 1944. A. E. HANDY ETAL 2,341,772

BELL HOIST Filed April 14, 1945 2 Sheets-Sheet 1 FIQI V V (3m INVENTORSBY 1 y If!!! ATTORNEY Feb. 15, 1944. A; E. HANDY ET Al.

BELL' HOIST Filed April 14, 1945 2 Sheets-Sheet 2 INVENTORS PatentedFeb. 15, 1944 BELL HOIST Arthur Edward Handy, Lynbrook, N. Y., andValdemar Bertelsen, Bogota, N. .L, assig'nors to Otis Elevator Company,New York, N. Y.,

a corporation of New Jersey Application April 14, 1943, Serial N0.483,074

1 Claim.

The invention relates to blast furnace bell hoists.

In charging a blast furnace, it is common practice to carry the stock inskips to the top of the furnace where it is dumped onto a small bell.The small bell is then opened to dump the stock onto a large bell andreclosed. This cycle of operation is repeated until a certain number ofloads have been dumped onto the large bell whereupon after the smallbell has been reclosed the large bell is opened to dump the charge intothe furnace. The large bell is then closed and the operation isrepeated. This gives the desired charge to the furnace and maintains aneffective seal at the top. The bells are biased to closed positions bycounterweights; Occasionally an explosion takes place in the compartmentbetween the two bells resulting in the forced opening of the large bell.After the pressure is relieved the large bell is reclosed by itscounterweight and in case the bell has been opened very wide the bellmay slam in closing.

The object of the invention is to provide bell operating mechanism inwhich slamming of the bell in closing is obviated.

In carrying out the invention an arrangement is provided which does notaffect the normal operation of the large bell but which, in the event ofabnormal operation of the bell such as would take place in the event ofan explosion between bells, causes the large bell to close at asufiiciently low speed to prevent damage to the apparatus when the bellseats under the action of the counterweight.

Features and advantages of the invention will become apparent from thefollowing description and appended claim.

n the drawings:

Figure l is a simplified schematic representation of a blast furnaceinstallation embodying the invention;

Figure 2 is an enlarged detail-in side elevation and with parts brokenaway of the counterweight and retarding mechanism for the large bell;and

Figure 3 is a view taken along the line 33 of Figure 2.

For a general understanding of the invention, reference may be had toFigure 1. The blast furnace II is provided at the top with a hopper [2for receiving the stock from the skip buckets. Upon the stock beingdumped into the hopper it falls on the small bell 13. The small bell inturn dumps the stock on the. large bell l4. When a specified number ofloads have been dumped onto the. large. bell,. the. large bell dumps thecharge into the furnace. The small bell is connected by a hollow rod E6to one end of lever I1. At its opposite end lever I1 is connected byroping 8 to 'a counterweight 29, passing over idler pulley 2|. Thiscounterweight is of sulficient mass to counterbalance the weight of thebell and the rod plus the weight of the load of stock resting on thebell. The counterweight is guided in its upward and downward movement onguides 22. Similarly, large bell I4 is connected to a lever 23 by a rod24 which extends through hollow rod 16. Lever 23 is likewise connectedby roping 25 to a counterweight 26, passing over idler pulley 21. Thecounterweight counterbalances the weight of the bell and the rod as wellas the weight of stock resting on the bell. The counterweight is guidedin its upward and downward movement by guides 28.

The hoisting machine for the bells comprises two drums 3B and 3t whichare loosely mounted on a shaft 32 supported by bearing pedestals mountedon base 33. Roping 34 is connected at one end to drum 3i and extendsupwardly over idler pulleys 35 and 36 and thence downwardly where itsotherend is connected to small bell counterweight 20. Roping 31 isconnected at one end to drum 30 and extends upwardly over idler pulleys38 and 40 and thence downwardly Where its other end is connected tolarge bell counterweight 2'0. Rotation of drum 3| from the neutralposition shown causes roping 34 to lift counterweight 20, therebyopening small bell I3. Rotation of drum 30 from neutral position causesroping 31 to lift counterweight 26, thereby opening large bell [4.

A drivinggear 42 is keyed t6 shaft 32. A lug i3 is provided on each sideof the gear. A lug 44 To close the small bell, the direction of rotationof gear 42 is reversed to allow drum 3| to return .to neutral under theinfluence of counterweight 20. A similar lug 45 is arranged on drum 30in the path of movement of the other lug 43 on gear 42 so as to beengaged thereby when gear 42 is rotated from neutral in the oppositedirection.

Continued rotative movement of the gear after lug 45 is engaged causesrotation of drum 30 to open'the large bell. In closing the large bell,

the direction of rotation of gear 42 is reversed to allow drum 30 toreturn to neutral under the infiuence of counterweight 26. Driving gear42 is driven by a pinion 46 on shaft 41 supported at its outer end by anadditional bearing pedestal mounted on base 33. The other end of shaft4! is driven by a worm gear arranged in casing 48 mounted on base 33.The driving worm for the worm gear is driven by an electric motor 50also mounted on base 33. An electro-mechanical brake is provided forbringing the rotating members rapidly to rest when the motor isdeenergized.

To prevent the slamming of the large bell in closing in the event it hasbeen blown open by an explosion in the chamber between the bells, thecounterweight 26 for the large bell is provided with a retarderdesignated as a whole as 50. Referring to Figures 2 and 3, the largebell counterweight comprises a plurality of weights 6| illustrated asheld together by means of clevis bolts 62 extending through the weights.A plate 83 is arranged between the clevis ends of the bolts and theweights while another plate 64 is arranged between the nuts 65 on thelower ends of the bolts and the weights. The clevis end of the bolts areutilized for securing the roping 25 and 31 to the counterweight.Channels 66 are secured to the weights, one on each side thereof, andsupport guide shoes 6'? at the upper and lower ends. The guides 28 forthe guide shoes are secured at their bottoms as by angles 68 to a base10. I

The retarder 59 comprises a plunger H which is secured to the bottom ofthe counterweight as by having the plate 64 welded to the top of theplunger. This plunger extends downwardly into a cylinder 12. Thecylinder has a flange 13 secured thereto as by welding which in turn ismounted on base 70 to form a support for the cylinder. The upper end ofthe cylinder extends into an oil reservoir M. This reservoir is securedto the cylinder as by welding at to form a leak-proof joint. Thisreservoir is also supported on a frame 16 secured to the guide rails 28.An opening 1'! is provided in top of the reservoir through which theplunger H extends. The upper end of the cylinder is provided with apacking gland T3 to prevent the leakage of oil out of the top of thecylinder. This packing gland is wholly within the reservoir so thatshould any oil leak out of the top of the cylinder it is returned to thereservoir. A bafile 80 extends downwardly from the top of the reservoirto the top of the packing gland to prevent oil being splashed outthrough the opening 11 around the plunger.

The bottom of the cylinder is connected to the bottom of the oilreservoir. This is effected by a pipe 8! secured to the bottom of thereservoir and connected at its lower end by means of an elbow 82 to avalve chamber 83. The valve chamber 83 has an opening at the top thereofconnecting with an :opening 84 in the base 85 of the cylinder. the valvechamber and biased by gravity to engage valve seat 81 and thus close theconnection from the valve chamber to pipe 8|. This valve is opened,however, upon raising of the plunger H within the cylinder, to permitthe passage of oil from the reservoir into the bottom of the cylinder.The side of the cylinder at a point just below reservoir 14 is alsoconnected to the bottom of the reservoir. This is effected by a .pipe 90.securedtothe bottom of the reser- A hinged valve 66 is arranged withinvoir and. connected at its lower end by means of an elbow 9| to a valvechamber 92. The left hand end of the valve chamber is connected as by ashort pipe 93 to the side of the cylinder. A regulating valve 94illustrated as of the globe valve type is provided in valve chamber 92to regulate the amount of oil exchange which can take place between thereservoir and the side of the cylinder. This valve is set to restrictthe flow of oil from the cylinder back into the reservoir duringdownward movement of the counterweight to such extent as to prevent thismovement taking place above a certain speed.

During normal operation of the furnace the retarder does not afiect thespeed of either the opening or the closing of the large bell. Uponopening of the large bell, the plunger moves upwardly in the cylinder asthe counterweight is lifted and check valve 86 opens to permit freepassage of oil by way of pipe 8| into the bottom of the cylinder. Uponclosing of the large bell,

the plunger moves downwardly into the cylinder 7 but as valve 86 is thenclosed the downward movement of the plunger forces oil from the cylinderby way of pipe 93 and valve 92 back into the reservoir. In a normalclosing operation, the rate at which the bell is moved by thecounterweight is determined by the rate at which drum' 30 is rotated bythe motor 50. During such closing movement, the valve 92 does not offersufficient restriction to the flow of oil to retard the closing of thebell. Should an explosion take place in the chamber between the bells,the large bell is blown open, pulling its counterweight upwardly. Oilflows as before by way of pipe 8| into the bottom of the cylinder as theupward movement of the plunger takes place so that the downward movementof the bell is not interfered with. This causes slack in roping 31 andas soon as the pressure in the chamber between the bells dropssufficiently the counterweight acts to close the bell. Without theretarder the speed of closing would be such that when the bell seatssevere stresses would be set up in the rod, lever, roping and otherparts of the apparatus, which might result in breakage of certain of theparts with consequent damage. The retarder acts, however, to cause thedownward movement of the counterweight to be gradual and hence theclosing of the bell to be below an objectional rate. This is due tovalve 92 which regulates the flow of oil from the cylinder back to thereservoir and thus determines the speed at which the counterweightdescends.

As many changes could be made in the above construction and manyapparently widely different embodiments of this invention could be madewithout departing from the scope thereof, it is intended that all mattercontained in the above description or shown in the accompanying drawingsshall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

In blast furnace charging mechanism havingv a small bell and a largebell; a counterweight for biasing the small bell to closed position; acounterweight 'for biasing the large bell to closed position; meansfor'opening each bell against the opening in the topthereof-ithroughwhich said connecting means extending from the side of said cylinder tosaid reservoir; and a second valve in said additional connecting meansadjusted to restrict the flow of oil from said cylinder to saidreservoir to retard lowering of said plunger in said cylinder by saidlarge bell counterweight in the event the large bell is blown open by anexplosion between the bells.

ARTHUR EDWARD HANDY. VALDEMAR BERTELSEN.

